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One random subject:
The adjacency matrix of the whole brain.
Segments: Bottom left: Left Hemisphere Upper right: Right Hemisphere
On average:
Segments: Bottom left: Left Hemisphere Upper right: Right Hemisphere
Compare left and right hemisphere in average
Degree plot by ROI index
Degree distribution 
2. Age related degeneration
Plot of the age (in weeks)
weeks<- covariates$AGE_WEEKS
plot(weeks)
quantile(weeks,c(0.25,0.75))## 25% 75%
## 62.7 78.0so we use 63 and 78.0 to divide mice into three groups: young,middle and old.
Adjacency matrices of the three groups
Young:
## [1] 9
Middle:
## [1] 12
Old:
## [1] 4
Obviously, old group seems significantly more degenerate than the young and middle, while the difference beween young and middle is more subtle.
Degree distribution of the 3 age groups:
Young mice have higher level of connectivy (degree) than the middle and old.
Use of dimension reduction:
We applied joint embedding on the 24 subjects and extract the diagonal distinct vectors
Pairs plot of the first 5 dimensions:
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## `stat_bin()` using `bins = 30`. Pick better value with `binwidth`.
## `stat_bin()` using `bins = 30`. Pick better value with `binwidth`.
## `stat_bin()` using `bins = 30`. Pick better value with `binwidth`.
## `stat_bin()` using `bins = 30`. Pick better value with `binwidth`.
Average scree plots of the 3 groups:
From the low dimension representation, old group looks distinct from the middle and young groups. This is consistent with the finding in the adjacency plots.